As the popularity of the Internet and wireless communications continues to grow, an increasing number of people are accessing the Internet and communicating with wireless user equipments (UEs). These UEs include (but are not limited to) cell phones, personal digital assistants (PDAs), handheld computers, laptop computers, Blackberries, and other types of portable or mobile computing systems. UEs may be used to retrieve electronic mail (email) messages, stock quotes, sporting event scores, weather forecasts, and various other information available from numerous web sites and their associated web pages.
E-mail messages are generally sent to an e-mail server that stores received messages in the recipient's e-mail mailbox. The user later retrieves these messages with either a web browser or an e-mail client that uses one of a number of e-mail retrieval protocols. While some clients and servers may use vendor-specific, proprietary protocols, most support the Internet standard protocols, i.e., SMTP for sending e-mail and Internet Message Access Protocol (IMAP) or Post Office Protocol (POP) for retrieving e-mail, allowing interoperability with other servers and clients. The current version of IMAP, version 4 revision 1 (IMAP4rev1), is defined by RFC 3501. There are a number of existing “push mail” products commercially available where an email server automatically notifies a UE when a new email addressed to the user of that UE is received at the email server. That email notification is sometimes called “push mail” because the email server automatically sends the email notification to the UE without the UE first requesting it.
Today's push mail applications unfortunately create a serious drain on the UE battery. Every time a new mail notification is sent to the UE, the UE leaves a very low power conservation state and enters into a higher power consuming state for a certain amount of time. One a higher power consuming state is entered, there is also often a fixed time period during which the UE must remain in that state before returning to a low power conservation state. Given the volume of email received by the average UE user, this battery drain is a significant problem.
Frequent email notifications can be particularly problematic when the UE battery is at a low level. Further drain on low charge level batteries resulting from continuing push mail notifications can result in disabling the UE so that other functions (receiving or transmitting a call, using data processing UE functions, etc.) can not be used. If the battery runs out because of frequent pushed mails, the user may be interrupted right in the middle of a document, message formulation, or some other task, and that work may be lost.
What is needed is a way for a UE to automatically control the volume and type of email (and any other pushed data) that is communicated to the UE based on the battery power level of the UE.